Co@Carbon and Co 3 O4@Carbon nanocomposites derived from a single MOF for supercapacitors

• Published in: Scientific reports Vol. 7; no. 1; pp. 1 - 11
• Main Authors: Dai, Engao, Xu, Jiao, Qiu, Junjie, Liu, Shucheng, Chen, Ping, Liu, Yi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group 03-10-2017
• Subjects: Capacitance; Carbon; Cobalt; Composite materials; Electrodes; Ion transport; Metal oxides; Metals; Morphology; Nanocomposites; Nanoparticles; Porosity; Pyrolysis; Surface area; Surface charge
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-12733-5

Developing a composite electrode containing both carbon and transition metal/metal oxide as the supercapacitor electrode can combine the merits and mitigate the shortcomings of both the components. Herein, we report a simple strategy to prepare the hybrid nanostructure of Co@Carbon and Co3O4@Carbon by pyrolysis a single MOFs precursor. Co-based MOFs (Co-BDC) nanosheets with morphology of regular parallelogram slice have been prepared by a bottom-up synthesis strategy. One-step pyrolysis of Co-BDC, produces a porous carbon layer incorporating well-dispersed Co and Co3O4 nanoparticles. The as-prepared cobalt-carbon composites exhibit the thin layer morphology and large specific surface area with hierarchical porosity. These features significantly improve the ion-accessible surface area for charge storage and shorten the ion transport length in thin dimension, thus contributing to a high specific capacitance. Improved capacitance performance was successfully realized for the asymmetric supercapacitors (ASCs) (Co@Carbon//Co3O4@Carbon), better than those of the symmetric supercapacitors (SSCs) based on Co@Carbon and Co3O4@Carbon materials (i.e., Co@Carbon//Co@Carbon and Co3O4@Carbon//Co3O4@Carbon). The working voltage of the ASCs can be extended to 1.5 V and show a remarkable high power capability in aqueous electrolyte. This work provides a controllable strategy for nanostructured carbon-metal and carbon-metal oxide composite electrodes from a single precursor.